A rising cancer rate has been detected in regions along the Huaihe River, Yang Gonghuan, former deputy director of the Chinese Center for Disease Control and Prevention, said.
The cancer rate in the affected areas was 50 percent higher than the national average of 0.25 percent in 2004-05, the study found.
The 620-mile Huaihe River runs through Henan, Anhui and Jiangsu provinces, all of which have seen rapid economic development since the 1980s.
Pollution from factories making leather and paper and manufacture plastic goods have affected water quality, Yang said, and many smaller factories with poor pollution control practices make the situation worse.
Some areas that had low cancer rates in the 1970s now have high rates, she said.
"These places happened to be seriously affected by water pollution in the Huaihe River", showing a correlation between water quality and cancer, she told the China Daily. "The study has great public health significance as we've spotted the most affected areas, which would help with more targeted cancer intervention efforts in the long run."